中国耕地空间格局演化对耕地适宜性的影响及政策启示

The Impact of Spatial Pattern Evolution of Cultivated Land on Cultivated Land Suitability in China and Its Policy Implication

研究目标:分析近20年中国耕地空间格局演化及其对耕地适宜性的影响,并据此提出耕地保护政策优化策略。研究方法:生态位模型和重心模型。研究结果:(1)中国耕地重心持续向西北迁移,2005年后迁移加速。北方干旱和半干旱区、东北平原区耕地加速增加,其他农业区耕地持续减少。耕地扩张热点区主要分布于新疆、东北平原,收缩热点主要分布于环渤海、长三角、珠三角和黄土高原;(2)中国耕地适宜性下降2.6%,降水和积温适宜性下降最明显。北方干旱和半干旱区耕地适宜性下降10.0%,其他农业区降幅较小或呈现波动趋势;(3)中国自然条件强限制耕地增加19.9%,降水和积温强限制耕地大幅增加,而侵蚀强限制耕地面积明显减少,北方干旱和半干旱区、东北平原区强限制耕地大幅增加,其他农业区均减少。研究结论:应通过国土空间规划优化耕地空间格局,加强国家对耕地“占补平衡”的引导控制,差异化实施耕地保护政策,有效提升耕地适宜性。

The purpose of this paper is to analyze the impact of spatial pattern evolution of cultivated land on cultivated land suitability in China in recent 20 years,so as to put forward the adjustment strategy of cultivated land protection policy.The methods of niche models and barycenter model were employed.The results show that:1)the center of gravity of cultivated land in China continued to move to the northwest and accelerated after 2005.The area of cultivated land increased rapidly in the arid and semi-arid areas of North China and the plain area of Northeast China,while the area of cultivated land in other agricultural areas continued to decrease.The hot spots of cultivated land expansion are mainly distributed in Xinjiang and Northeast Plain,while hot spots of cultivated land shrinkage are mainly distributed in the Bohai Sea,Yangtze River Delta,Pearl River Delta and Loess Plateau.2)The cultivated land suitability in China decreased by 3.2%,the suitability of precipitation and accumulated temperature decreased most obviously.The suitability of cultivated land in arid and semi-arid areas in the north of China decreased by 10.0%,while that in other agricultural regions showed a small or fluctuating trend.3)The area of cultivated land with obvious limiting factors increased by 19.9%,mainly due to the increasing area of cultivated land restricted by precipitation and accumulated temperature,while the area of cultivated land restricted by erosion decreased significantly.The areas of restrictive cultivated land increased greatly in the arid and semi-arid areas of North China and the plain area of Northeast China,but decreased in other agricultural areas.In conclusion,the spatial pattern of cultivated land should be optimized through land spatial planning,strengthen the guidance and control of the“balancing cultivated land occupation and reclamation”,and implement the policy of cultivated land protection differently to effectively improve cultivated land suitability.